1. Field of the Invention
This invention relates to a multilayer thin film structure and a process for manufacturing the structure and mounting it on an electronic packaging substrate.
2. Description of Related Art
An improvement in the method for producing multilayer thin film (MLTF) structures was disclosed in U.S. Pat. No. 5,258,236, assigned to the assignee of the present application, which involved building the MLTF structure as a "decal" on a transparent carrier. Between the MLTF structure and the carrier was a polyimide layer which served as a release layer to remove the MLTF structure from the carrier prior to joining it to a ceramic substrate. The release method disclosed was a laser ablation of the polyimide layer through the transparent substrate material. While the method of the '236 patent was successful in permitting simultaneous fabrication of the multilayer thin film interconnection structure and a ceramic substrate before the two are joined, it had the limitation that an external frame was required to be attached to the MLTF structure decal prior to release from the carrier on which it was formed. This led to a relatively cumbersome alignment and lamination process which involved high temperature adhesives. The framing of the decal and the process of the '236 patent also did not achieve high productivity in building the MLTF structure on the carrier since it required setting aside for handling purposes a frame area on each side of the individual MLTF decal sections, or "chicklets". This reduced the productive surface area on the carrier by up to 50%.
U.S. Pat. Nos. 4,480,288, 4,743,568, 4,950,527, 5,274,912, 5,286,335, and 5,329,695; and IBM TDB Vol. 21, No. 5, Vol. 27, No. 3, and Vol. 32, No. 5B disclose other manufacturing methods related to integrated circuit chips, some of which are also applicable to thin film structures. However, these references do not overcome the problems discussed above, or have other deficiencies which make them less desirable.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a MLTF structure and method of fabrication which eliminates the need for additional framing and aligning equipment to join the MLTF structure to an electronic packaging substrate.
It is another object of the present invention to provide an improved MLTF manufacturing method which increases the yield on the carrier substrate on which it is formed.
A further object of the invention is to provide an improved method of transferring a MLTF structure to a substrate to form a single chip module (SCM) or multi-chip module (MCM).
It is yet another object of the present invention to provide a method of manufacturing and joining a MLTF structure to a substrate which increases productivity while reducing costs.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.